Joint CFO and Channel Estimation for OFDM-Based Two-Way Relay Networks

Author

Wang, Gongpu ; Gao, Feifei ; Wu, Yik-Chung ; Tellambura, Chintha

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Alberta, Edmonton, AB, Canada

Volume

10

Issue

2

fYear

2011

fDate

2/1/2011 12:00:00 AM

Firstpage

456

Lastpage

465

Abstract

Joint estimation of the carrier frequency offset (CFO) and the channel is developed for a two-way relay network (TWRN) that comprises two source terminals and an amplify-and-forward (AF) relay. The terminals use orthogonal frequency division multiplexing (OFDM). New zero-padding (ZP) and cyclic-prefix (CP) transmission protocols, which maintain the carrier orthogonality and ensure low estimation and detection complexity, are proposed. Both protocols lead to the same estimation problem which can be solved by the nulling-based least square (LS) algorithm and perform identically when the block length is large. We present detailed performance analysis by proving the unbiasedness of the LS estimators at high signal-to-noise ratio (SNR) and by deriving the closed-form expression of the mean-square-error (MSE). Simulation results are provided to corroborate our findings.

Keywords

OFDM modulation; amplify and forward communication; channel estimation; least squares approximations; mean square error methods; CFO; OFDM-based two-way relay networks; TWRN; amplify- and-forward relay; carrier frequency offset; channel estimation; cyclic-prefix transmission protocols; mean-square-error; nulling-based least square algorithm; orthogonal frequency division multiplexing; signal- to-noise ratio; two-way relay network; Carrier frequency offset; OFDM; channel estimation; performance analysis; two-way relay network;

fLanguage

English

Journal_Title

Wireless Communications, IEEE Transactions on

Publisher

ieee

ISSN

1536-1276

Type

jour

DOI

10.1109/TWC.2010.120310.091615

Filename

5659868